Interesting that someone said Sirius red does not stain amyloid! It is just one
of the dyes used to stain a variant of the amyloid protein, hope I said
that correctly.  

Years ago, if our congo red CI 22120 (aka "Direct red") did not work, we sent 
slides off to AFIP to have a sirius red done!  The differences in staining
can be caused by different types of amyloid, hence, trying other dyes.

Sirius red F3B is the one used, CI number 22120, Direct Red 4B has a different
CI number, 23500, indicating a different dye than the Sirius Red F3B.
In fact, potassium permanganate reaction can help differentiate forms
of amuloidosis.  

Some oldies but goodies, articles that explain differences in amyloid
proteins, Al, AA just to name a few and how they stain.    


J Pathology, Cohen et al,  Pathogenesis and biochemistry of amyloidosis,
151-1-10, 1987

Stain Technology Elghetany et al, Methods for staining amyloid in
tissues, a review 63:201-21, 1988

Laboratory Medicine  Hinds IL  Congo Red-Sirius Red technique for amyloid,
	16:366, 1985

Laboratory Investigation, Wolman M.  Amyloid, its nature and molecular
structure 25:104-110, 1971

Laboratory Investigation, Wright JR et al, Potassium permangante 
reaction in amyloidosis, 36:274-281, 1977

American Journal of Pathology, van Rijswijk MH.  The potassium 
permangate method, 97:43-54, 1979.   This article talked about a 
classification system (is it still used?) for amyloidosis:
Primary, myeloma associated, secondary, localized and familial

J Histoetechnology Waldrop FS et al  Fluorescent thiazole stains for
amyloid without differentiation, 7:123-126,1984.

Hope this helps, now to go back to my modified Puchler-Sweat congo
red amyloid staining today.

Gayle Callis

Gayle Callis